KR101450280B1 - Protection of broadcast signals in heterogeneous networks - Google Patents

Abstract

Certain aspects of the present disclosure provide protection of broadcast signals in heterogeneous networks. As described herein, a first set of resources used for downlink transmission of a first cell may overlap a first set of resources used for broadcast signals of a second cell. The broadcast signals are protected by assigning a third set of resources for downlink transmission of the first cell, where the third set of resources is based, at least in part, on a superposition set of resources.

Description

[0001] PROTECTION OF BROADCAST SIGNALS IN HETEROGENEOUS NETWORKS [

Priority Claim

This application is a continuation-in-part of U.S. Provisional Application No. 61 / 288,154, filed December 18, 2009, which is assigned to the assignee hereof and is expressly incorporated herein by reference, and whose title is "Protection Of Broadcast Signals In Heterogeneous Networks" .

Field of invention

BACKGROUND I. Field [0002] The present disclosure relates generally to communication, and more specifically to power control in a multi-carrier wireless communication network.

Wireless communication networks are widely deployed to provide a variety of communication content such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multi-access networks capable of supporting multiple users by sharing available network resources. Examples of such multiple-access networks include, but are not limited to, code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) SC-FDMA) networks.

A wireless communication network may include multiple base stations capable of supporting communication of multiple user equipments (UEs). The UE may communicate with the base station on the downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE and the uplink (or reverse link) refers to the communication link from the UE to the base station.

The base station may transmit data to one or more UEs on the downlink and may receive data from one or more UEs on the uplink. On the downlink, data transmission from the base station can observe interference due to data transmissions from neighboring base stations. On the uplink, data transmission from the UE may observe interference due to data transmissions from other UEs communicating with neighboring base stations. For both the downlink and uplink, interference due to interfering base stations and interfering UEs may degrade performance.

Certain aspects of the present disclosure provide a method for wireless communications in a wireless communication network. The method generally includes: determining a first set of resources for downlink transmission from a first cell to one or more first user equipments (UEs); Determining a second set of resources for use in transmitting broadcast signals to one or more second UEs in a second cell, the first and second sets of resources being at least partially overlapping in time and frequency Including a superposition set of resources; And allocating a third set of resources for downlink transmission of the first cell, wherein the third set of resources is based, at least in part, on a superposition set of the resources.

Certain aspects of the present disclosure provide apparatus for wireless communications in a wireless communication network. The apparatus generally comprises means for determining a first set of resources for downlink transmission from a first cell to one or more first user equipments (UEs); Means for determining a second set of resources for use in transmitting broadcast signals to one or more second UEs in a second cell, the first and second sets of resources at least partially overlapping in time and frequency; Including a set of resources to perform; And means for allocating a third set of resources for downlink transmission of the first cell, wherein the third set of resources is based, at least in part, on a superposition set of resources,

Certain aspects of the present disclosure provide apparatus for wireless communications in a wireless communication network. The apparatus generally determines a first set of resources for downlink transmission from a first cell to one or more first user equipments (UEs), and transmits broadcast signals to one or more second UEs in a second cell Wherein the first set of resources and the second set comprise a superposition set of resources at least partially overlapping in time and frequency, the downlink transmission of the first cell The third set of resources being based, at least in part, on a superposition set of the resources; And a memory coupled to the at least one processor.

Certain aspects of the present disclosure provide a computer program product for wireless communications that includes a computer-readable storage medium having stored thereon instructions. Instructions generally determine a first set of resources for downlink transmission from a first cell to one or more first user equipments (UEs), and transmit broadcast signals to one or more second UEs in a second cell Wherein the first set of resources and the second set comprise a superposition set of resources at least partially overlapping in time and frequency, the downlink transmission of the first cell The third set of resources being executable by the processor to be based, at least in part, on a superposition set of the resources.

Figure 1 illustrates an exemplary heterogeneous wireless communication network in accordance with certain aspects of the present disclosure.
2 illustrates a block diagram of exemplary components of an access point and an access terminal in accordance with certain aspects of the present disclosure.
Figure 3 illustrates exemplary components of a wireless communication system in accordance with certain aspects of the present disclosure.
4 illustrates exemplary operations for allocating resources in accordance with certain aspects of the present disclosure.
Figure 5 illustrates examples of carrier segments and extended carriers in accordance with certain aspects of the present disclosure.
6 illustrates examples of physical downlink shared channel resources extended according to certain aspects of the present disclosure.
Figure 7 illustrates an exemplary FDD frame with broadcast signals to be protected in accordance with certain aspects of the present disclosure.

Various aspects are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It will be appreciated, however, that such aspect (s) may be practiced without these specific details.

As used herein, the terms "component," "module," "system," and the like are intended to include a computer-related entity such as a combination of hardware, firmware, software and hardware, software, But are not limited thereto. For example, a component may be, but is not limited to, a process running on a processor, a processor, an object, an executable, an execution thread, a program, and / or a computer. For example, both an application running on a computing device and a computing device may be components. One or more components may reside within a process and / or thread of execution, and the component may be localized on one computer and / or distributed between two or more computers. These components may also be executed from various computer readable media having various data structures stored thereon. Components may communicate with other components via a network (e.g., the Internet) with other systems in a distributed system and / or with signals (e.g., in a local system, And / or remote processes according to the data (e.g., data from one component operating).

Also, various aspects are described in connection with a terminal that may be a wired terminal or a wireless terminal. A terminal is also referred to as a system, a device, a subscriber unit, a subscriber station, a mobile station, a mobile, a mobile device, a remote station, a remote terminal, an access terminal, a user terminal, . The wireless terminal may be a cellular telephone, a satellite telephone, a cordless telephone, a Session Initiation Protocol (SIP) telephone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a portable device with wireless connection capability, Lt; / RTI > Also, various aspects are described herein in connection with a base station. A base station may be utilized to communicate with the wireless terminal (s) and may also be referred to as an access point, Node B, eNode B (eNB), or some other terminology.

Also, the word "or" is intended to mean " exclusive "or" rather than " That is, the phrase "X uses A or B" is intended to mean any natural inclusive permutations, unless otherwise specified or clear from the context. That is, the following examples using the phrase "X uses A or B ", that is, X uses A; X uses B; Or X is satisfied by any of those using both A and B. Also, the objects used in the singular to the present specification and the appended claims should generally be construed to mean "one or more ", unless the context clearly dictates otherwise or singularly.

The techniques described herein may be used for various applications such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA ) Networks, and the like. The terms "networks" and "systems" are often used interchangeably. CDMA networks can implement radio technologies such as general purpose terrestrial radio access (UTRA), CDMA 2000, and the like. UTRA includes wideband-CDMA (W-CDMA) and low chip rate (LCR). CDMA 2000 covers IS-2000, IS-95 and IS-856 standards. The TDMA network may implement radio technologies such as Global System for Mobile Communications (GSM).

The OFDMA network may implement radio technologies such as E-UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, Flash-OFDMDM, UTRA, E-UTRA and GSM are part of the Universal Mobile Telecommunications System (UMTS). Long Term Evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents from the organization named "3rd Generation Partnership Project" (3GPP). CDMA 2000 is described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). These various radio technologies and standards are known in the art. For clarity, certain aspects of the techniques are described below for LTE and LTE terminology is used in most of the descriptions below.

Single carrier frequency division multiple access (SC-FDMA) utilizing single carrier modulation and frequency domain equalization has similar performance and essentially the same overall complexity as that of an OFDMA system. The SC-FDMA signal has a lower peak-to-average power ratio (PAPR) due to its inherent single carrier structure. SC-FDMA has attracted considerable interest in uplink communications, which are particularly advantageous for mobile terminals in view of lower transmission power efficiency, especially at lower PAPRs.

1 illustrates an exemplary heterogeneous wireless network 100 on which various aspects of the present disclosure may be implemented.

The wireless communication network 100 may be an LTE network or some other wireless network. The wireless network 100 may include multiple evolved Node Bs (eNBs) 110 and other network entities. The eNB may be an entity that communicates with the UEs, and may also be referred to as a base station, a Node B, an access point, and so on. Each eNB may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to an eNB's coverage area and / or an eNB subsystem that serves this coverage area depending on the context in which the term is used.

The eNB may provide communication coverage for macro cells, picocells, femtocells, and / or other types of cells. The macrocell may cover a relatively large geographic area (e.g., a few kilometers in radius) and may allow unrestricted access by UEs that have subscribed to the service. A picocell can cover a relatively small geographic area and allow unrestricted access by UEs that have subscribed to the service. A femtocell may cover a relatively small geographic area (e.g., home) and may also be used by UEs (e. G., Closed Subscriber Group (CSG) ). ≪ / RTI > An eNB for a macro cell may be referred to as a macro eNB. An eNB for a picocell may be referred to as a pico eNB. The eNB for the femtocell may be referred to as a home eNB (HeNB) or a femto eNB. 1, the eNB 110a may be a macro eNB for the macro cell 102a, the eNB 110b may be a pico eNB for the picocell 102b, and the eNB 110c may be a femto May be a femto eNB for cell 102c. The eNB may support one or more (e.g., three) cells. The terms "eNB", "base station", and "cell" may be used interchangeably herein.

The wireless network 100 may also include repeaters. A repeater may be an entity capable of receiving a transmission of data from an upstream station (e.g., an eNB or UE) and transmitting a transmission of data to a downstream station (e.g., a UE or an eNB). The repeater may also be a UE capable of relaying transmissions to other UEs. In the example shown in Figure 1, the relay 110d is connected to the UE 120d via an access link and the macro eNB 110a via a backhaul link to facilitate communication between the eNB 110a and the UE 120d. Communication can be performed. The repeater may also be referred to as a repeater eNB, a repeater station, a repeater base station, or the like.

The wireless network 100 may be a heterogeneous network that includes different types of eNBs, e.g., macro eNBs, pico eNBs, femto eNBs, repeater eNBs, and the like. These different types of eNBs may have different impacts on interference in the wireless network 100, different coverage sizes, and different transmission power levels. For example, macro eNBs may have a high transmit power level (e. G., 5 to 40 watts), while pico eNBs, femto eNBs, and repeaters may have lower transmit power levels To 2 watts).

The network controller 130 may be coupled to a set of eNBs and may provide control and control for these eNBs. The network controller 130 may comprise a single network entity or a collection of network entities. The network controller 130 may communicate with the eNBs via a backhaul. eNBs may also communicate with each other indirectly or directly via, for example, a wireless or wired backhaul.

The UEs 120 may be distributed throughout the wireless network 100 and each UE may be stationary or mobile. A UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, and so on. The UE may be a cellular telephone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a portable device, a laptop computer, a cordless telephone, a wireless local loop (WLL) station, a smartphone, a netbook, The UE may be capable of communicating with macro eNBs, pico eNBs, femto eNBs, repeaters, and the like. The UE may also be capable of communicating peer-to-peer (P2P) with other UEs. In the example shown in Figure 1, UEs 102e and 120f may communicate directly with each other without communicating with the eNBs in the wireless network 100. [ P2P communication may reduce load on wireless network 100 due to local communications between UEs. P2P communication between UEs may also allow one UE to function as a relay for another UE, thereby enabling another UE to connect to the eNB.

In Figure 1, a solid line with double arrows indicates the desired transmissions between the serving eNB and the UE, which are eNBs designated to serve the UE on the downlink and / or uplink. A dotted line with double arrows indicates interference transmissions between the UE and the eNB.

The UE may be located within the coverage of multiple eNBs. One of these eNBs may be selected to serve the UE. The serving eNB may be selected based on various criteria such as received signal strength, received signal quality, path loss, and the like. The received signal quality can be quantified by a signal-to-noise and interference ratio (SINR), or a reference signal reception quality (RSRQ), or some other metric.

The UE may operate in a dominant interference scenario where the UE can observe high interferences from one or more interfering eNBs. Dominant interference scenarios may occur due to restricted association. For example, in FIG. 1, UE 120c may be close to femto eNB 110c and may have a high received power for eNB 110c. However, the UE 120c may not be able to access the femto eNB 110c due to limited associativity, and may then access the macro eNB 110a with the lower received power. UE 120c may then observe high interference from the femto eNB 110c on the downlink and may cause high interference to the femto eNB 110c on the uplink.

A dominant interference scenario may also occur due to range extension, which is a scenario in which a UE connects to an eNB with a lower path loss and possibly a lower SINR among all eNBs detected by the UE. For example, in FIG. 1, the UE 120b may be located closer to the pico eNB 110b than the macro eNB 110a and may have a lower path loss to the pico eNB 110b. However, the UE 120b may have a lower received power for the pico eNB 110b than the macro eNB 110a due to the lower transmit power level of the pico eNB 110b compared to the macro eNB 110a. Nevertheless, it may be desirable for UE 120b to connect to pico eNB 110b due to lower path loss. This may result in less interference to the wireless network for a given data rate for UE 120b.

Various interference management techniques can be used to support communication in dominant interference scenarios. These interference management techniques may include anti-static resource partitioning (which may be referred to as inter-cell interference coordination (ICIC)), dynamic resource allocation, interference cancellation, and the like. Semi-static resource partitioning may be performed to allocate resources to different cells (e.g., through backhaul negotiation). The resources may include subframes, subbands, carriers, resource blocks, transmit power, and the like. Each cell may be assigned a set of resources that can be observed at all or rarely from interference from other cells or their UEs. Dynamic resource allocation may also be used to allocate resources needed to support communications to UEs that are observing strong interference on the downlink and / or uplink (e.g., over-the-air between cells and UEs over-the-air) messages. The interference cancellation may also be performed by the UEs to mitigate interference from the interference cells.

The wireless network 100 may support hybrid automatic repeat request (HARQ) for data transmission on the downlink and uplink. In HARQ, a transmitter (e.g., an eNB) may transmit one or more transmissions of a packet until the packet is correctly decoded by a receiver (e.g., a UE) or some other termination condition is encountered. For synchronous HARQ, all transmissions of a packet may include a single HARQ interlace (which may include every Q-th subframes, where Q may be equal to 4, 6, 8, 10, or any other value) frames of interlaces may be transmitted. For asynchronous HARQ, each transmission of a packet may be transmitted in any subframe.

The wireless network 100 may support synchronous or asynchronous operation. In synchronous operation, eNBs may have similar frame timing, and transmissions from different eNBs may be roughly time aligned. For asynchronous operation, the eNBs may have different frame timings, and transmissions from different eNBs may not be temporally aligned.

The wireless network 100 may utilize FDD or TDD. For FDD, the downlink and uplink may be allocated separate frequency channels, and the downlink transmissions and uplink transmissions may be transmitted simultaneously on two frequency channels. In TDD, the downlink and uplink may share the same frequency channel and the downlink and uplink transmissions may be transmitted on the same frequency channel in different time periods.

Protection of broadcast signals in heterogeneous networks

As illustrated, according to certain aspects, different eNBs of heterogeneous wireless network 100 may be assigned to physical downlink shared channel (PDSCH) for their UEs through application of extended carriers and / or carrier segments May be configured to "extend" resources. As illustrated, the macro eNB 110a may communicate with the femtocell 102c over the PDCCH 132 in a manner that extends the PDSCH for the UE 102c by allocating a portion of the component carrier used by the UEs served in the femtocell 102c. Resources can be allocated. Similarly, the macro eNB 110b may allocate resources via the PDCCH 134 in a manner that extends the PDSCH for the UE 120b by allocating a portion of the component carrier used by the UEs served in the macrocell 102a. Can be assigned.

As will be described in greater detail below, the assignment may be done in a manner designed to "protect " the broadcast signals necessary for the UE to reliably decode for proper operation. This protection is achieved by careful allocation of resources used for downlink transmission of a first cell ("interfering cell") overlapping resources allocated for broadcast signals of a second cell ("interfering cell" .

For example, in the carrier utilization case, the transmission of specific broadcast signals (e.g., PBCH / PSS / SSS) of some cells (e.g., low power class nodes) (E.g., high power class nodes) by allocating resources to avoid using resource blocks (RBs) used for broadcast signals. As described in detail below, there may be various options for achieving this protection.

As one illustrative but non-limiting example, a first cell may utilize the resources of a first component carrier (CC) for a physical downlink shared channel (PDSCH) and "extend " "can do. The resources of the second CC used for the extended PDSCH may overlap with the resources used to transmit the broadcast signals of the second cell. The broadcast signals may therefore be protected by allocating resources of the second CC that are used to extend the PDSCH in a manner that attempts to avoid interference with resources used for the broadcast signals of the second cell.

FIG. 2 is a block diagram 200 illustrating exemplary components of an exemplary base station 210 and an access terminal 250 of an exemplary wireless system 200. As shown in FIG. The base station 210 may be an eNB or an access point, such as one of the eNBs 110 illustrated in FIG. 1, and the access terminal 250 may be a user equipment such as one of the UEs 120 illustrated in FIG. .

At base station 210, traffic data for a number of data streams is provided from a data source 212 to a transmit (TX) data processor 214. Processor 230 may generate control information to be transmitted to AT 250. [ As illustrated, the processor 230 may receive resource allocation information indicating how different resources are allocated among different cells of the heterogeneous network. According to particular aspects, the resource allocation information may indicate a set of resources used to transmit broadcast signals of different cells (e.g., "interfered cells"). As described below, this information may be used to protect broadcast signals by allocating resources for downlink transmission of the current cell such that the broadcast signals do not interfere with the broadcast signals in other cells.

The resource allocation information may be exchanged, for example, via a backhaul connection (not shown in FIG. 2) and may be the result of resource negotiations. Thus, the resource allocation information may change over time as the negotiations change according to the variable network conditions. In any case, processor 230 may utilize this information to generate the appropriate PDCCH to be transmitted in the downlink transmission to allocate resources to AT 250 for use as PDSCH (or extended PDSCH).

The TX data processor 214 formats, codes, and interleaves the traffic data for that data stream based on a particular coding scheme selected for each data stream to provide coded data. The coded data for the control information and data streams may be multiplexed with the pilot data using OFDM techniques.

The pilot data is a known data pattern that is typically processed in a known manner and can be used in the receiver system to estimate the channel response. The multiplexed pilot and coded data for each data stream is then combined with a particular modulation scheme selected for that data stream (e.g., Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK) (E.g., symbol mapped) based on an M-PSK (where M is typically a power of two) or M-QAM (Quadrature Amplitude Modulation)). The data rate, coding, and modulation for each data stream may be determined by instructions performed by processor 230 that may be coupled to memory 232.

The modulation symbols for all data streams are then provided to a TX MIMO processor 220 which may further process the modulation symbols (e.g., for OFDM). TX MIMO processor 220 then provides N _T modulation symbol streams to N _T transmitters (TMTR) 222a through 222t. In certain aspects, the TX MIMO processor 220 applies beamforming weights to the symbols of the data streams and to the antenna that is transmitting the symbols.

Transmitters 222 receive and process symbol streams for each downlink component carrier to provide one or more analog signals and further condition (e.g., demodulate) the analog signals to provide a modulated signal suitable for transmission over the MIMO channel (E.g., amplifies, filters, and upconverts). N _T modulated signals from transmitters 222a through 222t are then transmitted from N _T antennas 224a through 224t, respectively.

At the access terminal 250, the transmitted modulated signals for the downlink component carriers are received by N _R antennas 252a through 252r and the signal received from each antenna 252 is transmitted to the receivers 254a through 252d, 254r are provided to their respective receivers (RCVRs). Each receiver 254 conditions (e.g., filters, amplifies, and downconverts) its respective received signal, digitizes the encoded signals to provide samples, and provides a corresponding " To further process the samples.

RX data processor 260 receives and processes the N _R received symbols from the N _R receivers 254 and then based on a particular receiver processing technique to provide N _T of "detected" symbol streams. The RX data processor 260 then provides control information and traffic data, including PDSCHs, and broadcast signals (which may be protected by careful resource allocation in potential interference cells as described herein) Deinterleaves, and decodes each detected symbol stream for each configured component carrier to recover.

The processing by the RX data processor 260 may be complementary to the processing performed by the TX data processor 214 and the TX MIMO processor 220 of the transmitter system 210. [ The processor 270 coupled to the memory 272 periodically determines which pre-coding matrix to use (discussed below). Processor 270 forms an uplink message including a matrix index portion and a rank value portion.

Processor 270 may, for example, receive PDSCH (or extended PDSCH) and resource allocation information for broadcast signals. The processor 270 may determine which resources are used for these signals based on this information.

The uplink (reverse link) message may include various types of information regarding the communication link and / or the received data stream. The uplink message is then processed by a TX data processor 238 that also receives traffic data for a number of data streams from data source 236, modulated by modulator 280, and transmitted by transmitters 254a through 254r ). ≪ / RTI >

Uplink transmissions from the access terminal 250 are received by the antennas 224 to extract the reverse link messages sent by the receiver system 250 and transmitted to the receivers 222 Demodulated by the demodulator 240, and processed by the RX data processor 242. The processor 230 may then determine various parameters, such as which pre-coding matrix to use to determine the beamforming weights, and continue processing the extracted message.

As mentioned above, in systems in which multi-carrier operation is supported, the UE may be configured to monitor and serve by two or more component carriers (CCs). In such systems, cross-carrier signaling may be supported in an effort to provide efficient control. This may be desirable in the context of heterogeneous networks where different types of cells (e.g., macros, pico and femtocells) with access points that transmit at variable power levels are overlaid.

For example, different types of CCs may exist to provide backward compatibility to UEs ("legacy" UEs) that are compatible with the standards of earlier versions. This combination of CCs can lead to improved UE throughput as well as more efficient interference management especially for heterogeneous networks. As described herein, some of the resources of the CC (e.g., carrier segments or extended carriers) may be used to extend the PDSCH of the (non-legacy) UE.

In accordance with certain aspects, an effort to reduce the interference between the portions of the CC used for the downlink transmissions of the first cell and those of the same CC used to transmit the broadcast signals of the second cell care can be performed. These broadcast signals include, for example, a physical broadcast channel (PBCH), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a common reference signal (CRS), a channel status information reference signal .

3 illustrates an exemplary communication system 300 that can protect broadcast transmissions on the CCs of one cell, also used for downlink transmissions in one or more other cells. As mentioned above, this can be achieved by a coordinated resource allocation in which different sets of resources are allocated in an effort to reduce interference between broadcast signals and downlink transmissions of other cells. As in FIG. 1, the interference transmissions are indicated by dashed lines.

As illustrated, the system 300 includes a base station 302 of a first cell (referred to herein as an "interfering base station") and a base station 304 of a second cell (referred to herein as a "interfering base station") do. Each of the base stations 302/304 and 306 may operate in a manner similar to the base stations and UEs described in connection with Figs. In accordance with particular aspects, in a multi-carrier operation, base station 302 or base station 304 may generate allocation information for extending the PDSCH of UE 304 across multiple carriers. In such cases, the assignment may be performed in an effort to reduce interference between broadcast signals of the other cells transmitted using the same CC resources and the extended PDSCH.

Transmissions from the interfering base station 302, as illustrated, may interfere with transmissions from the interfering base station 304, for example, to a user equipment (UE) that properly decodes signals transmitted from the interfering base station 304. [ ; 306). ≪ / RTI > Although not shown, any number of base stations similar to the interfering base station 302 and / or the interfering base station 304 may be included in the system 300 and / or any number of UEs, similar to the UE 306, It is foreseen that it can be included in the network 300.

System 300 may be a heterogeneous network in which nodes of different power classes (e.g., base stations such as interfering base station 302 and interfering base station 304) co-exist. In such systems, UEs (e.g., UE 306 or disparate UEs not shown) may observe strong interference on the downlink from nodes from different power class cells. In one example, in a closed-subscriber-group (CSG) cell, the macro-UE is not allowed to access the CSG cell, but the macro-UE can observe strong downlink (DL) interference from the CSG cell, Effectively creating a coverage hole.

Various techniques can be used to manage such interference attempts to reduce such interference in the context of co-channel deployment. By way of example, blank or "almost-blank" subframes (ABSF) in which one or more base stations avoid or restrict transmissions on one or more subframes (and thus appear to be blank) Time Division Multiplexing (TDM) -based resource management. Interference from the interfering cells may be reduced through blank subframes. In the "almost" blank subframes, the data area may be entirely blank, while the control field may be a PCFICH (physical) channel, except for the transmission of a Physical Downlink Control Channel (PHICH) Control Format Indicator Channel). In addition, the transmit power of higher power class nodes may be reduced to approximate heterogeneous networks, despite the risk of potentially reducing macrocell coverage.

The use of multiple carriers may also help to reduce interference. In accordance with this example, the interfering base station 302 may comprise a carrier aggregation component 308 and the interfering base station 304 may comprise a carrier aggregation component 310. The carrier aggregation component 308 and the carrier aggregation component 310 may enable aggregation of consecutive and / or non-consecutive spectra such that the UEs have access to the corresponding physical layer (PHY) resources . In accordance with certain aspects, resource allocation from one carrier to another may be enabled through the use of an agreed ' Carrier Indicator Field ' embedded in the PDCCH. The carrier aggregation component 308 and the carrier aggregation component 310 may implement one or more non-backward compatible concepts, such as, for example, carrier extensions (segments) and extended carriers.

As illustrated, the interfering base station 304 may further include a broadcast component 312 capable of transmitting broadcast signals on the downlink on a particular CC. Unfortunately, downlink data transmissions sent by interfering base station 302 using a physical downlink shared channel (PDSCH) may overlap resources used to transmit broadcast signals.

In an effort to avoid interference between the PDSCH transmissions and the broadcast signals of the interfering base station 304, the interfering base station 302 may use an interference management component 314 that can manage interference using the techniques described herein . In accordance with certain aspects, the interference management component 314 may exchange information about the resources utilized by the interfering base station 304 to transmit broadcast signals over the backhaul link 320.

FIG. 4 illustrates exemplary operations 400 that may be performed by, for example, interfering base station 304 to protect broadcast signals in accordance with certain aspects of the present disclosure. The base station performing these operations may be as described in connection with any of Figs. For example, the exemplary operation 400 may be supervised by one or more processors (e.g., processor 230), or one or more components (e.g., components 308 through 314) .

At 402, the base station determines a first set of resources for downlink transmission to one or more first user equipments (UEs) of a first cell. At 404, the base station determines a second set of resources for use in transmitting broadcast signals to one or more second UEs in a second cell, wherein the first and second sets of resources are at least partially Lt; RTI ID = 0.0 > nested < / RTI > At 406, the base station allocates a third set of resources for the downlink transmission of the first cell, where the third set of resources is based, at least in part, on a superposition set of resources. Depending on the particular aspects, the third set of resources may comprise a subset of the first set of resources. Depending on the particular aspects, transmissions utilizing the first set of resources (not the third set of resources) may be performed with zero power (accordingly, conventional mappings may be utilized, Power control to protect it).

The techniques presented here can be used to protect broadcast signals of one cell from interference by downlink transmissions of other cells. This protection is based on the knowledge of the resources allocated to transmit broadcast signals in the interfering cell (or potentially interfering cell), so that careful attention to resources on downlink transmissions in the interfering (or potential interference) Lt; / RTI >

In various systems such as LTE "Advanced" (LTE-A), carrier aggregation enables aggregation of consecutive or non-consecutive spectra such that UEs have access to corresponding PHY resources. Resource allocation from one carrier to another carrier may be enabled. As an example, this may be enabled through the use of the agreed-upon carrier indication field (CIF) embedded in the PDCCH. As another example, this may be enabled by treating the carriers of aggregation as a single carrier in the context of resource assignment, especially in the case of carrier extensions detailed below.

To extend the PDSCH, different mechanisms outside the primary CC may be used, such as carrier extensions (segments) and extended carriers. As used herein, the term carrier segments generally refer to segments that are defined as a bandwidth extension of an existing (e.g., LTE Rel-8 compatible) component carrier (typically not greater than a total of 110 RBs). The carrier segment may allow utilization of frequency resources when new transmission bandwidths are required in a backward compatible manner that complements the carrier aggregation means. This mechanism may reduce the additional PDCCH transmissions that would be required for the carrier aggregation setting and may also reduce the use of small TB sizes for the portion corresponding to the segment. Thus, the carrier segment may allow the aggregation of additional resource blocks for the component carrier while still maintaining backward compatibility of the original carrier bandwidth. Carrier segments can always be defined as being adjacent (and not used "stand-alone") to a component carrier at all times. The carrier segments may also be limited in their use, for example, not providing synchronization signals, system information, or paging.

Diagram 510 of FIG. 5 illustratively illustrates exemplary carrier segments (segment 1 and segment 2) adjacent to a component carrier (carrier 0) that is backwards compatible with LTE Rel.8. As mentioned, the segments are extensions of the CC, and thus a CC with extension (s) can be considered as a single HARQ entity. The assignment of one or more extensions for use in extending the PDSCH may be made on the PDCCH of carrier 0.

The extended carriers may be designed in a philosophy similar to the carrier segments. However, the extended carrier may itself be an actual component carrier that may or may not be backward compatible (with Rel-8 UEs). The backward compatible carrier and the extended carrier, which are two different component carriers, may assume independent H-ARQ processes and transport blocks.

Diagram 520 of FIG. 5 illustrates an exemplary extended carrier (Carrier 1) linked to a backward compatible component carrier (Carrier 0). As mentioned, the extended carrier may be an actual component carrier and thus be treated as an independent HARQ entity. Again, the assignment of an extended carrier for use in extending the PDSCH may be made on the PDCCH of carrier zero.

As shown in FIG. 5, extended carriers and carrier segments may be linked to a backwards compatible component carrier, and in some cases may not be used in an independent manner. The use of extended carriers and / or segments allows for the use of synchronization signals, system information, paging for UEs and their use for conveying various control channels such as Rel-8 PDCCH, Rel-8 PHICH, and Rel-8 PCFICH To be prohibited. In addition, these extension mechanisms may be prohibited for use in random access or UE camping. The extended carriers and segments may not be recognized and / or accessible by LTE Rel8 ("legacy") UEs.

The use of such carrier aggregation mechanisms in the proposed heterogeneous networks (HetNs) is advantageous for high power nodes (e.g., macro UEs) and low power nodes (e.g., femto / pico nodes UEs Lt; RTI ID = 0.0 > a < / RTI > According to particular aspects, the extended carriers and carrier segments may be suitable for interference management on HetNets. In this case, different parts of the spectrum may be interpreted differently by different types of nodes.

For example, as illustrated in resource diagram 610 of FIG. 6, an extended PDSCH for a high power node may include an extended carrier (not shown), which may comprise one backward compatible carrier CC1 and a second component carrier CC2 (EC2) or at least one carrier segment (CS1). Legacy UEs (e.g., Rel-8 or earlier) can be served only within CC1, while non-legacy UEs (Rel-9 or later) Lt; RTI ID = 0.0 > CS1 / EC2. ≪ / RTI > However, as illustrated, the allocation of resources of CS1 / EC2 can be made through the control area 612 of CC1.

It should be noted that diagram 610 of FIG. 6 represents an exemplary interpretation of the spectrum available in terms of high power nodes. On the other hand, diagram 650 represents an exemplary interpretation of the same spectrum in terms of low power nodes. As illustrated, in terms of low power nodes, the extended PDSCH includes one backward compatible carrier CC2 and one or more of the extended carrier (s) EC1 or carrier segment (s) CS2, or component carriers CC1 ). In this example, a backward compatible CC2 can carry the control domain and signal resources for EC1 / CS2 / CC1. In this case, the mapping of the PDSCH of EC1 / CS2 / CC1 specified from CC2 starts from the OFDM symbol (or fixed OFDM symbol) which is transmitted to the UE by CC2. In this example, EC1 / CS2 does not convey the control domain, but rather CC1 delivers the normal control channel.

As illustrated above, due to this arrangement, different parts of the spectrum can be interpreted differently by different types of nodes. In general, when high power nodes do not transmit in symbols using CS1 or EC2 that conflict with the control region of lower nodes using CC2, the high power nodes < RTI ID = 0.0 > And low power nodes may be arranged.

In accordance with certain aspects, resources for the "extended PDSCH" may include resources for high power node broadcast signals (e.g., because legacy broadcast signals are transmitted on CC2 by low power nodes) Lt; RTI ID = 0.0 > and / or < / RTI > According to certain aspects, the symbols of the RBs used to transmit the broadcast signals (or the entire resource blocks (RBs)) may be avoided when transmitting the extended PDSCH.

For example, by exchanging resource partitioning information (e.g., via backhaul connections), the Node Bs can communicate with the control domain 624 (e.g., corresponding to the control domain of the high power node) ≪ / RTI > may be able to schedule resources in this manner to avoid interference between the broadcast signals transmitted at the base station. Interference avoidance can be achieved, for example, by avoiding RBs used to transmit broadcast signals by the low power node of CC2 when allocating resources for the extended PDSCH to other nodes.

Non-legacy UEs "(e. G., &Quot; non-legacy UEs ") while CS1 or EC2 of high power nodes may be transparent to" legacy UEs "(e.g. those compatible with LTE Rel- , Those that are compatible with future releases such as Rel-10 or later) can be scheduled (cross-carrier scheduling) to the PDCCH being transmitted on CC1 of high power nodes. Depending on the interference management schemes, the transmit power of the data area of CS1 or EC2 may be significantly higher than the transmit power of CC2, resulting in severe interference to CC2. To mitigate this issue, backhaul information exchange or resource allocation information can be used to control the cells involved.

For low power class nodes, the UEs served by CC2 may need to reliably decode the various broadcast signals transmitted from CC2 for proper operation. These broadcast signals may include PBCH, PSS, SSS, CRS, and the like. The transmission of the PBCH, PSS and SSS typically occupies some of the symbols of the six resource blocks in the center of the system. This is illustrated in FIG. 7 which illustrates an exemplary radio frame illustrating the resources utilized for the PBCH, PSS and SSS in the FDD system.

According to one example, a (potentially) interfering base station may transmit a PBCH / PSS / SSS of the interfered cells (e.g., as transmitted by the broadcast component 312 of the interfering base station 304) The broadcast signals can be protected by avoiding transmitting on the downlink using the symbols of the six RBs (or the entire group of these RBs) in the middle of the subframes that will collide with the symbols / subframes . If the interfering base station 302 schedules overlapping PDSCHs with these six RBs, the interference management component 314 punctures or rates-matches those six RBs, Only the remaining symbols are used in these six RBs, or the entire RBs are avoided.

In another example of protecting broadcast signals, if (the demodulation of) the colliding PDSCH on the interfering base station 302 is based on the CRS, then the interference management component 314 may determine that the PDSCH is < Matched around the symbols that conflict with the symbols of the PBCH / PSS / SSS of the affected cells (as transmitted by the cast component 312). On the other hand, if (the demodulation of) the colliding PDSCH on the interfering base station 302 is based on the UE-RS, the interference management component 314 may be configured such that the PDSCH is rate- matched around it, .

As another example, the interfering base station 302 may transmit its PDSCH rate-matched around the CRS tones for the affected cells. Thus, the interference management component 314 may cause the interfering base station 302 to signal to the UE associated therewith.

The interfering base station 302 may transmit the PDSCH and puncture the tones whose CRS tones are transmitted for the affected cells. This operation may be transparent to the UEs associated with the interfering base station 302. The interfering base station 302 may selectively puncture its CRS tones based on the projected interference to its affected cells. That is, the interfering base station 302 may at least reserve those symbols of the corresponding subframes that conflict with the symbols of the PBCH / PSS / SSS / CRS of the cells requiring interference protection. This may allow detection of a reliable broadcast signal (e.g., PBCH / PSS / SSS) for the UE served by the affected cells.

Whether the interfering base station chooses to preserve some symbols or RBs for the purpose of minimizing interference to protect the transmission of broadcast signals from other cells depends on the power level differences, antenna gain, proximity between the participating cells, Such as UE variances / channel conditions, scheduling algorithms, quality of service (QoS) requirements, and / or one or more resource management schemes. The retention information can also be exchanged over a backhaul link between the involved cells for more efficient interference management.

It should be noted that in some synchronous systems, broadcast signals from different cells may collide with each other. Alternatively, the broadcast signals of different cells may not occur in the same subframes and / or may not completely overlap in a single subframe. Thus, to protect broadcast signals, the resource conservation described herein can span more than two subframes of the affected cell.

In accordance with other aspects, the above techniques described with reference to the PBCH, PSS, and SSS may also be applied to a channel state information-reference signal (CSI-RS) that may be introduced in a future release (e.g., Rel-10) Can be applied.

It can also be noted that if two or more affected cells do not have the same REs for broadcast signals, the interference cells need to accommodate the protection of the broadcast signals for these affected cells. In such cases, according to certain aspects, the interference cells may select only one (or only a selected set) of the affected cells to perform RE preservation. Depending on the particular aspects, this selection may be based on various factors such as channel conditions, loading, QoS, and the like. This information can be exchanged through the backhaul.

As an example of this selection, if the first cell (cell 1) interferes with the second and third cells (cell 2 and cell 3), the retention is made by making a broadcast transmission for cell 2, Only in a protected way can REs be preserved. This determination may be based, for example, on conditions such that cell 2 is more sensitive than cell 3 for interference from cell 1. According to another example, if cell 1 interferes with cell 2 and cell 3, preservation is done to protect broadcast transmissions for both cell 2 and cell 3 (e.g., by preserving REs for both) .

The present disclosure provides for the application of extended carriers and carrier segments in the context of heterogeneous networks while protecting broadcast signal transmission by other nodes. As described herein, different portions of the spectrum may be interpreted differently by different types of nodes.

The various illustrative logic blocks, modules, and circuits described in connection with the present disclosure may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array signal (FPGA) Logic devices (PLDs), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The steps of a method or algorithm described in connection with the present disclosure may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software modules may reside in any form of storage medium known in the art. Some examples of storage media that may be used include random access memory (RAM), read only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD- . A software module may contain a single instruction or multiple instructions and may be distributed among different programs and across several different code segments across multiple storage media. The storage medium may be coupled to the processor such that the processor can write information to the storage medium and read information from the storage medium. Alternatively, the storage medium may be integrated into the processor.

The methods described herein include one or more steps or operations to achieve the described method. The method steps and / or operations may be interchanged with one another without departing from the scope of the claims. That is, the order and / or use of certain steps and / or operations may be modified without departing from the scope of the claims, unless a specific order of steps or acts is specified.

The functions described may be implemented in hardware, software firmware, or any combination thereof. When implemented in software, the functions may be stored as one or more instructions on a computer-readable medium. The storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can be RAM, ROM, EEPROM, CD-ROM, other optical disk storage, magnetic disk storage or other magnetic storage devices, Or any other medium that can be used to carry or store desired program code in the form of structures. As used herein, a disk and a disc may be in the form of a compact disc (CD), a laser disc, an optical disc, a digital versatile disc (DVD) Discs, and Blu-ray discs, where discs usually reproduce data magnetically, while discs reproduce data optically through a laser.

For example, such a device may be coupled to a server to facilitate transfer of the means for performing the methods described herein. Alternatively, the various methods described herein may be provided via storage means (e.g., a RAM, ROM, a compact disc (CD) or a physical storage medium such as a floppy disk) so that the user terminal and / The various means are obtained when coupling or providing the means to the device. In addition, any other suitable technique for providing the devices and methods described herein to a device may be utilized.

It will be appreciated that the claims are not limited to the concise configurations and components illustrated above. Various modifications, changes, and variations can be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

While the foregoing is directed to aspects of the present disclosure, other and further aspects of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims (46)

A method for wireless communication in a wireless communication network,
Determining a first set of resources for downlink transmission to one or more first user equipments (UEs) in a first cell;
Determining a second set of resources for use in transmitting broadcast signals to one or more second UEs in a second cell, the first and second sets of resources being at least partially overlapping in time and frequency Including a superposition set of resources; And
Allocating a third set of resources for the downlink transmission in the first cell, the third set of resources being based, at least in part, on a superposition set of resources,
Lt; / RTI >
A method for wireless communication in a wireless communication network. The method according to claim 1,
Wherein the broadcast signals comprise:
A physical broadcast channel (PBCH), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a common reference signal (CRS) And a channel state information reference signal (CSI-RS).
A method for wireless communication in a wireless communication network. The method according to claim 1,
Wherein the third set of resources comprises a subset of the first set of resources.
A method for wireless communication in a wireless communication network. The method according to claim 1,
Wherein resources in the first set of resources that are not used for the downlink transmission comprise a subset of the set of resources or all superposition sets of the resources.
A method for wireless communication in a wireless communication network. 5. The method of claim 4,
The demodulation of the downlink transmission is based on a common reference signal (CRS)
A method for wireless communication in a wireless communication network. The method according to claim 1,
Wherein resources in the first set of resources that are not used for the downlink transmission comprise at least one additional resource in the first set of resources and all overlapping sets of resources.
A method for wireless communication in a wireless communication network. The method according to claim 6,
The at least one additional resource being in the same set of resource blocks as the overlapping set of resources,
A method for wireless communication in a wireless communication network. The method according to claim 1,
The wireless communication network includes a heterogeneous network,
Wherein the first and second cells are of different power class types,
A method for wireless communication in a wireless communication network. The method according to claim 1,
The downlink transmission utilizes a physical downlink shared channel (PDSCH)
A method for wireless communication in a wireless communication network. 10. The method of claim 9,
Wherein mapping of the modulated and coded symbols of the PDSCH does not utilize resources in the first set of resources other than the third set of resources,
A method for wireless communication in a wireless communication network. 10. The method of claim 9,
Wherein the mapping of the modulated and coded symbols of the downlink transmission utilizes resources in the first set of resources,
Wherein transmissions utilizing resources in the first set other than resources in the third set of resources are performed with zero-
A method for wireless communication in a wireless communication network. The method according to claim 1,
Exchanging information about at least one of the resources in the first set or the second set of resources through a backhaul connection between the first cell and the second cell
≪ / RTI >
A method for wireless communication in a wireless communication network. The method according to claim 1,
Wherein the downlink transmission in the first cell comprises at least one of a common reference signal (CRS), a channel state information reference signal (CSI-RS), or a combination thereof.
A method for wireless communication in a wireless communication network. The method according to claim 1,
Wherein the downlink transmission in the first cell is transmitted in an almost blank subframe (ABSF)
A method for wireless communication in a wireless communication network. The method according to claim 1,
Wherein the carrier of the first cell comprises at least one of an extended carrier or a carrier segment that is not backwards compatible with Long Term Evolution, Release 9 or earlier releases.
A method for wireless communication in a wireless communication network. An apparatus for wireless communication in a wireless communication network,
Means for determining a first set of resources for downlink transmission to one or more first user equipments (UEs) in a first cell;
Means for determining a second set of resources for use in transmitting broadcast signals to one or more second UEs in a second cell, the first and second sets of resources at least partially overlapping in time and frequency Including a set of resources to perform; And
Means for allocating a third set of resources for the downlink transmission in the first cell, the third set of resources being based, at least in part, on a superposition set of the resources,
/ RTI >
An apparatus for wireless communication in a wireless communication network. 17. The method of claim 16,
Wherein the broadcast signals comprise:
Wherein the at least one physical channel comprises at least one of a physical broadcast channel (PBCH), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a common reference signal (CRS), or a channel state information reference signal (CSI-
An apparatus for wireless communication in a wireless communication network. 17. The method of claim 16,
Wherein the third set of resources comprises a subset of the first set of resources.
An apparatus for wireless communication in a wireless communication network. 17. The method of claim 16,
Wherein resources in the first set of resources that are not used for the downlink transmission comprise a subset of the set of resources or all superposition sets of the resources.
An apparatus for wireless communication in a wireless communication network. 20. The method of claim 19,
The demodulation of the downlink transmission is based on a common reference signal (CRS)
An apparatus for wireless communication in a wireless communication network. 17. The method of claim 16,
Wherein resources in the first set of resources that are not used for the downlink transmission comprise at least one additional resource in the first set of resources and all overlapping sets of resources.
An apparatus for wireless communication in a wireless communication network. 22. The method of claim 21,
The at least one additional resource being in the same set of resource blocks as the overlapping set of resources,
An apparatus for wireless communication in a wireless communication network. 17. The method of claim 16,
The wireless communication network comprising a heterogeneous network,
Wherein the first and second cells are of different power rating types,
An apparatus for wireless communication in a wireless communication network. 17. The method of claim 16,
The downlink transmission utilizes a physical downlink shared channel (PDSCH)
An apparatus for wireless communication in a wireless communication network. 25. The method of claim 24,
Wherein mapping of the modulated and coded symbols of the PDSCH does not utilize resources in the first set of resources other than the third set of resources,
An apparatus for wireless communication in a wireless communication network. 25. The method of claim 24,
Wherein the mapping of the modulated and coded symbols of the downlink transmission utilizes resources in the first set of resources,
Wherein transmissions utilizing resources in the first set other than resources in the third set of resources are performed with zero-
An apparatus for wireless communication in a wireless communication network. 17. The method of claim 16,
Means for exchanging information about at least one of the resources in the first set or the second set of resources through a backhaul connection between the first cell and the second cell
≪ / RTI >
An apparatus for wireless communication in a wireless communication network. 17. The method of claim 16,
Wherein the downlink transmission in the first cell comprises at least one of a common reference signal (CRS), a channel state information reference signal (CSI-RS), or a combination thereof.
An apparatus for wireless communication in a wireless communication network. 17. The method of claim 16,
Wherein the downlink transmission in the first cell is transmitted in an almost blank subframe (ABSF)
An apparatus for wireless communication in a wireless communication network. 17. The method of claim 16,
Wherein the carrier of the first cell comprises at least one of an extended carrier or a carrier segment that is not backwards compatible with Long Term Evolution, Release 9 or earlier releases.
An apparatus for wireless communication in a wireless communication network. An apparatus for wireless communication in a wireless communication network,
At least one processor; And
A memory coupled to the at least one processor,
Wherein the at least one processor comprises:
Determining a first set of resources for downlink transmission to one or more first user equipments (UEs) in a first cell,
Determine a second set of resources for use in transmitting broadcast signals to one or more second UEs in a second cell, wherein the first and second sets of resources are at least partially overlapped in time and frequency Including a superposition set of
Wherein the third set of resources is configured to allocate a third set of resources for the downlink transmission in the first cell, the third set of resources being based, at least in part,
An apparatus for wireless communication in a wireless communication network. 32. The method of claim 31,
Wherein the broadcast signals comprise:
Wherein the at least one physical channel comprises at least one of a physical broadcast channel (PBCH), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a common reference signal (CRS), or a channel state information reference signal (CSI-
An apparatus for wireless communication in a wireless communication network. 32. The method of claim 31,
Wherein the third set of resources comprises a subset of the first set of resources.
An apparatus for wireless communication in a wireless communication network. 32. The method of claim 31,
Wherein resources in the first set of resources that are not used for the downlink transmission comprise a subset of the set of resources or all superposition sets of the resources.
An apparatus for wireless communication in a wireless communication network. 35. The method of claim 34,
The demodulation of the downlink transmission is based on a common reference signal (CRS)
An apparatus for wireless communication in a wireless communication network. 32. The method of claim 31,
Wherein resources in the first set of resources that are not used for the downlink transmission comprise at least one additional resource in the first set of resources and all overlapping sets of resources.
An apparatus for wireless communication in a wireless communication network. 37. The method of claim 36,
The at least one additional resource being in the same set of resource blocks as the overlapping set of resources,
An apparatus for wireless communication in a wireless communication network. 32. The method of claim 31,
The wireless communication network comprising a heterogeneous network,
Wherein the first and second cells are of different power rating types,
An apparatus for wireless communication in a wireless communication network. 32. The method of claim 31,
The downlink transmission utilizes a physical downlink shared channel (PDSCH)
An apparatus for wireless communication in a wireless communication network. 40. The method of claim 39,
Wherein mapping of the modulated and coded symbols of the PDSCH does not utilize resources in the first set of resources other than the third set of resources,
An apparatus for wireless communication in a wireless communication network. 40. The method of claim 39,
Wherein the mapping of the modulated and coded symbols of the downlink transmission utilizes resources in the first set of resources,
Wherein transmissions utilizing resources in the first set other than resources in the third set of resources are performed with zero-
An apparatus for wireless communication in a wireless communication network. 32. The method of claim 31,
Wherein the at least one processor comprises:
Exchange information about at least one of the resources in the first set or the second set of resources through a backhaul connection between the first cell and the second cell
Lt; / RTI >
An apparatus for wireless communication in a wireless communication network. 32. The method of claim 31,
Wherein the downlink transmission in the first cell comprises at least one of a common reference signal (CRS), a channel state information reference signal (CSI-RS), or a combination thereof.
An apparatus for wireless communication in a wireless communication network. 32. The method of claim 31,
Wherein the downlink transmission in the first cell is transmitted in an almost blank subframe (ABSF)
An apparatus for wireless communication in a wireless communication network. 32. The method of claim 31,
Wherein the carrier of the first cell comprises at least one of an extended carrier or a carrier segment that is not backwards compatible with Long Term Evolution, Release 9 or earlier releases.
An apparatus for wireless communication in a wireless communication network. 15. A computer-readable storage medium for wireless communication,
The instructions,
Determining a first set of resources for downlink transmission to one or more first user equipments (UEs) in a first cell,
Determine a second set of resources for use in transmitting broadcast signals to one or more second UEs in a second cell, wherein the first and second sets of resources are at least partially overlapped in time and frequency Including a superposition set of
Allocating a third set of resources for the downlink transmission in the first cell, the third set of resources being executable by the processor to, at least in part,
Computer-readable storage medium.

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